On high voltage lines, many problems, such as lightning striking the line, tree branches or wires blowing in a wind gust, or animals on the lines, are only temporary. However, even these temporary problems can cause permanent damage to electrical equipment if power is not shut off for their duration. A device such as a recloser may be used in high voltage lines to deal with such problems.
A recloser is an automatic, high-voltage electric switch that shuts off electric power in an electric distribution line when a problem, such as a short circuit, occurs. After shutting off power, and waiting for expiration of a time delay, the recloser automatically restores power and tests the distribution line to determine whether the problem has been removed. If the problem is still present, the recloser shuts off power again. The recloser may repeat the shut-off-wait-restore process several times. If the fault is permanent, the recloser may shut off the power permanently after a certain number of repetitions (for example, three or four).